PERIODIC PATTERN IRREGULARITY INSPECTION METHOD AND IRREGULARITY INSPECTION DEVICE

PROBLEM TO BE SOLVED: To provide a periodic pattern irregularity inspection method and irregularity inspection device capable of highly accurately discriminating between a normal part and an irregular part in an inspection target body having a periodic pattern, from contrast provided by diffracted light.SOLUTION: In step S1, operator operation means is used to input product information such as a pitch, a chip layout and a management number of an inspection target substrate to information processing means (an inspection target substrate information input process). Then in step S2, an X-Y- stage section and an alignment imaging section align the inspection target substrate (a positioning process). In step S3 and step S4, a processing/control section sets a lens magnification (an imaging magnification determination process). In step S5, the information processing means determines an illumination radiating angle on the basis of a diffraction grating equation (an illumination radiating angle determination process), and then inspection conditions are set on the basis of values obtained in the flow of step S3 to S6.